This invention relates to an automatic transformer testing apparatus, more particularly an apparatus for automatically testing the performances of a power transformer without requiring a testing operator repeatedly to disconnect-and-connect the power supply lines during the testing process so as to avoid the risk of high voltage electric shocks.
A power transformer for use in a power transmission system must pass a series of performance tests after it has been manufactured and before installation in the system. Such performance tests conventionally include a NO-LOAD LOSS TEST, a HIGH VOLTAGE ENDURANCE TEST, an INDUCTION VOLTAGE TEST, as well as other kinds of tests depending upon the specific application and relevant national codes. FIG. 1 shows a conventional testing station for conducting such performance tests, which station includes a plurality of testing tables 1A, 1B and 1C disposed in a test room 1; each testing table having one pair of clamps 2, 2', or 2" respectively connected to a central testing instrument 1D located outside test room 1. A power transformer (hereinafter referred to simply as a transformer) 3 is placed on a roller conveyor 1E and moved from a storage area to a first position corresponding to first testing table 1A where transformer 3 is first connected to central testing instrument 1D by clamping first pair of clamps 2" on to a pair of test terminals 4 of transformer 3 and then an appropriate voltage is applied to transformer 3 to conduct a first test, which may be the NO-LOAD LOSS TEST. As soon as the first test has been completed, first pair of clamps 2" is removed from test terminals 4 of transformer 3, and transformer 3 is moved to second test table 1B where a second test, which may be the HIGH VOLTAGE ENDURANCE TEST, is conducted in the same manner as the first test. Subsequent tests are conducted in the same manner. During the series of tests, clamps 2, 2', or 2" are manually clamped on and disconnected from test terminals 4 by a test operator, and transformer 3 is also pushed from one position to the next by a test operator. As the tests usually employ voltages as high as 10 KV, the test operator is exposed to the risk of electric shocks. Moreover, tests conducted by such conventional test apparatus are slow and inefficient.